Modern simulcast messaging systems are evolving towards ever increasing data rates to accommodate increasing messaging traffic. A promising solution for obtaining higher data rates is the use of quadrature amplitude modulation (QAM) techniques. In a system employing QAM, synchronization is a key determinant of system performance.
Simulcast systems pose unique challenges, in that multiple signals arrive at a messaging receiver with time-of-arrival offsets. It is the job of the synchronization system to properly synchronize the receiver in the presence of such distortion. Prior-art synchronization techniques are unable to estimate the time-of-arrival of synchronization signals accurately enough for desired QAM performance in a simulcast environment.
Thus, what is needed is a new, more accurate method and apparatus for estimating a time-of-arrival of a synchronization signal in a simulcast environment.